In the previous two posts on the paleontology of Rockford, Iowa, we looked at the site itself and the majority of the fossils, leaving the brachiopods for now. I ended up identifying 13 brachiopod taxa to genus or species. They're written up in alphabetical order below, with a brief description of what I found to be the most important distinguishing characteristics for those of us who know a thing or two about brachiopods but are not conversant with fine anatomical details. I have to admit that the photos are a bit disappointing, which is in part because we're dealing with strongly three-dimensional objects. Pictures are great, but there are things that just don't quite make sense unless you're holding a fossil in your hand. I used Fenton and Fenton (1924) quite a bit, recognizing that the taxonomy is outdated (brachiopod taxonomy does not sit still). I also consulted online galleries of Rockford fossils, e.g., this, this, and this, and had recourse to Ma and Day (2000) for the spiriferids. All in all, I'm happy with the identifications in a broad sense, but inevitably there are a few individual specimens that I'm not sure about.
Equatorial Minnesota
Minnesota paleontology and geology, National Park Service paleontology, the Mesozoic, and occasional distractions
Sunday, October 27, 2024
Sunday, October 13, 2024
Compact Thescelosaurus Year Nine
October and National Fossil Day have rolled around again (check out the fall 2024 Park Paleontology News, too!), so it's time to take a look at the previous year's changes to The Compact Thescelosaurus and welcome some new content. First, the new stuff: I'm sure you'll be shocked to find out I've followed up Triassic pseudosuchians with... Jurassic pseudosuchians. I'm rearranging the pseudosuchian content a bit, to have the non-crocodylomorphs on one sheet and the crocodylomorphs on another. This was done to forestall the deployment of an unwieldy number of "subdivision" columns. Provided I get far enough along, something similar might have to happen with the new sheet around Crocodylia or so. Anyway, the main takeaways I got out of Jurassic pseudosuchians are 1) there's been a lot of work on thalattosuchians over the past couple of decades, and 2) I've discovered I'm not very fond of thalattosuchians and certainly don't mind that they conk out midway through the Cretaceous.
Hey, it's the Science Museum "Goniopholis" again! (Most Jurassic pseudosuchians are thalattosuchians, but North America is largely bereft of the darlings, so we make do with crocs like these.) |
Monday, October 7, 2024
Rockford, Part 2: Fossils (exclusive of brachiopods)
Before we get into the festivities, I've recently written an article for the online magazine Agate, about identifying common Paleozoic fossils of Minnesota. It's a compact summary that covers the most abundant groups, so if you're looking for something like that, go have a look!
In our previous post we had a look at the geology of the Fossil & Prairie Park Preserve of Floyd County, Iowa, also known as the Rockford site. For this post I'm going to briefly detail the fossils I collected, with the exception of the brachiopods, which will get a post of their own. For most of the non-brachiopods, I didn't get too far into the weeds on taxonomy, because many of the groups don't lend themselves to simple eye-checks for genera and species. Horn corals and bryozoans, for example, usually require thin sections, and crinoid columnals are generally only diagnostic of the presence of crinoids. I did, though, have recourse to Fenton and Fenton (1924) and other peoples' identifications to get some ideas.
Sunday, September 29, 2024
Rockford, Part 1: The Site
A few weeks I was able to join a Geological Society of Minnesota field trip to the Fossil & Prairie Park Preserve of Floyd County, Iowa, which to some of you may be more familiar as the Rockford site. We ended up having a practically ideal day: pleasant temperatures, clear skies, dry conditions, and a light breeze. If you have an itch to collect fossils (an itch that's becoming difficult to legally scratch in Minnesota these days), I highly recommend a visit.
A view into the old quarry directly south of the parking area. |
Sunday, September 15, 2024
Your Friends The Titanosaurs: Qunkasaura pintiquiniestra
2024 has been a great year for new titanosaurs, as we are now on the fifth to be announced and we're still more than three months from the end of the year. For a change of pace, this time we're heading to Europe. Qunkasaura pintiquiniestra, the first new European titanosaur in more than two and a half years, hails from the Lo Hueco site in Spain.
Sunday, August 25, 2024
Fona herzogae
This whole thing started from a website called Thescelosaurus!, so unsurprisingly I'm particularly interested when an old-fashioned "hypsil" metaphorically crosses my desk. Our (belated) guest today is the new genus and species Fona herzogae. Before we get into the meat of the post, I would also like to throw a kind word to the iguanodontian Comptonatus chasei Lockwood et al. (2024), published online the same day. (Yes, it *did* make me think of Camptonotus, which would have been Camptosaurus had somebody not pinned it to a cricket first.)
Sunday, August 11, 2024
An unexpected mammoth
While visiting Wisconsin's Interstate Park over the weekend (happy 80th birthday, Smokey Bear!), I was surprised to come across another resident of the Cottage Grove area at the Ice Age Center:
According to the display, this mammoth tooth was discovered on Grey Cloud Island on July 9, 1987, by Arnold Sanford of Frederic, Wisconsin. This is the kind of thing that makes me wish we had an update to Stauffer "1945". (Even if I have to do it myself.) There must be plenty of other post-WWII finds scattered across Minnesota that are only known locally. When I was a little kid, my mother told me that part of a mammoth tooth had been found in Red Wing by a Boy Scout; I've never been able to find anything about it, but it certainly wouldn't surprise me!
Incidentally, the Ice Age Center also has other fossils and cast fossils of Ice Age mammals from the area. (Interstate Park is the western terminus of the Ice Age National Scenic Trail and one of the components of Ice Age National Scientific Reserve.) The most significant are bison bones and a cast skull from the park's bison bonebed, discovered in 1936 during CCC work. The bonebed is in my hopper of topics; until then, here are the specimens on display.
References
Stauffer, C. R. “1945” [at least 1948 based on dates in the article]. Some Pleistocene mammalian inhabitants of Minnesota. Minnesota Academy of Science Proceedings 13:20–43.